The invention aims at providing a sound and reliable coupling for releasably securing one end of a rod-like member.
In the preferred embodiments later to be described, the rod-like member is a hollow tube or pipe intended for conveying fluids, more particularly liquids. When such pipes are employed, the coupling of the invention can be utilized for joining the ends of adjacent pipe lengths or for joining the end of a pipe length to a junction or union. Two or more such couplings may be utilized at the junction or union to secure the ends of pipes leading thereto. The rod-like member need not necessarily be a pipe and references to "rod-like member" are intended to encompass solid or hollow rods, bars or tubes of circular or any other appropriate cross-section. In such case couplings can be utilized to anchor the terminal end of such a rod-like member or, again, to join appropriate members in end-to-end relationship.
Traditional and conventional methods of joining or coupling the ends of pipes or rod-like members involve screw-threaded arrangements of bayonet-type fasteners. The problems involved in utilizing bayonet-type fasteners in, for example, inserting a junction union into a pipe system will be immediately appreciated since such fasteners necessarily entail relative movement of the members to be joined. Screw-threaded fasteners, whether in the form of an end-to-end join or a lateral screw-threaded clamping pin can suffer from the disadvantages of loosening over time and, more particularly, lack of ease in assembly.
The present invention aims to obviate such disadvantages and provide a very expedient and rapid coupling which can be completely assembled and clamped by a simple one-quarter turn of a locking element.
Applicants have conducted an exhaustive search through the principal and related classes encompassing couplings, connections and joints. That search has revealed a volume of prior art but none of the prior art revealed and considered, either singly or in combination, anticipates or renders obvious the novel invention of this application.
Typical of a lateral screw-threaded coupling is U.S. Pat. No. 3,951,436 to Hyde. That Hyde patent discloses pipe ends disposed one within the other and a lateral screw-threaded clamp extending through the outer pipe end to abut and clamp the inner pipe end on tightening rotation.
Another common traditional way of clamping concentric members one within the other is to drive a wedge or plurality of wedges between the two members. Such a wedging arrangement can be utilized either to join pipe ends or to secure a rod-like member within a bushing. Typical of such a wedge clamping arrangement are U.S. Pat. Nos. 3,806,215 and 3,971,186 to Havelka, et al.
Of all the prior art considered, perhaps the most relevant is U.S. Pat. No. 3,992,118 to Slegers. Slegers utilizes a wedging principle to clamp a curved plate on to the peripheral surface of a tubular member. To drive the wedge into operative clamping arrangement, a collar is rotatable around the tubular member and over the wedge element. That collar has a cam surface which abuts a stationary projection on the tubular member to advance the collar into the wedging position. Although the most relevant of the considered prior art, Slegers is really only relevant insofar as it does utilize a camming principle. There the similarity stops and the necessity of providing an otherwise redundant collar on and around the assembly detracts from the compact nature of the coupling and also ease of coupling.
The foregoing discussed prior art discloses clamping by screw-threaded engagement or by the driving of wedge means between two members to be clamped. These two distinct concepts can be combined and U.S. Pat. No. 3,941,410 to Miyaoka and No. 3,472,533 to Vincent et al. combine these principles to advance a wedge into clamping position by means of screw-threaded tightening of controlling screw means. U.S. Pat. No. 1,611,912 to Hleb is also concerned with a screw propelled wedge movable into and out of an operative clamping position.
In addition to the screw-threaded and wedge controlled couplings, it is generally known to lock two members in the desired position by means of locking pins which, in the simplest concept, drop into registering apertures in members to be joined. Exemplary of such locking pins are U.S. Pat. No. 3,735,928 to Watts, et al., 3,425,632 to Stout and No. 3,243,213 to Proctor. In all these prior patents, the locking pin is merely dropped into position in an accommodating slot.
A fourth and final common mode of coupling a pipe member is the provision of bayonet slots in the pipe member arranged to engage positioning pins. Such bayonet couplings are evidenced in U.S. Pat. No. 2,494,855 to Anderson and No. 3,885,648 to Beziat. It will be appreciated that absent some additional restraining means, a simple bayonet-type coupling will not provide the firm and reliable fluid type joint as is provided by the invention. Moreover, there is no cam controlled locking as is taught by the present invention.
This foregoing recitation and brief analysis of the prior art encountered by the all encompassing search is concerned only with releasable couplings of the general class with which the present invention is concerned. Thus, there has been no discussion of permanent coupling by welding of two members.